The parents of a three-year-old boy born with a devastating, life-limiting genetic condition say they are now excited for his future after he received a revolutionary stem cell gene therapy treatment developed by researchers at the University of Manchester.
In February this year, Oliver (Ollie) Chu, was treated for Hunter syndrome in a clinical study being delivered at Royal Manchester Children’s Hospital (RMCH) in collaboration with the Manchester Centre for Genomic Medicine at Saint Mary’s Hospital – both part of Manchester University NHS Foundation Trust (MFT) The trial is managed and sponsored by the University of Manchester.
Children with Hunter syndrome, a rare, inherited condition also known as mucopolysaccharidosis type II (MPS II), have an error in a gene, meaning they cannot produce an important enzyme that breaks down complex sugar molecules. Over time these sugars build up in organs and tissues, leading to joint stiffness, hearing loss, breathing and heart problems, developmental delays and cognitive decline, resembling childhood dementia. Hunter syndrome can be life-threatening, with life expectancy typically between 10 and 20 years. Currently the only licensed drug that can help to improve life for children with Hunter syndrome is Elaprase – a weekly enzyme replacement therapy that takes approximately three hours, that children must take for their whole life. Approximately 50 patients in the UK receive Elaprase, which costs around £375,000 a year per patient. The drug can reduce mobility and organ problems but cannot improve mental decline.
Now, several months on from the procedure, Ollie has fully recovered from the transplant, and his parents and the Manchester researchers are excited by his progress.
The clinical study at RMCH is investigating a one-off gene therapy which involves removing the child’s stem cells, replacing the faulty gene and re-injecting the modified cells into the patient. These stem cells can produce high levels of the missing enzyme and also reach the brain.
Professor Rob Wynn, Consultant Paediatric Haematologist and Director of Paediatric Bone Marrow Transplant Programme at RMCH and joint clinical lead, said: ““For many years we have performed bone marrow transplant for children with Hunter Syndrome and similar illnesses. However, these are difficult procedures that can only deliver as much enzyme as the donor’s blood naturally has.
“Gene therapy is not only safer and more effective, but it enables us to use the child’s own cells which cuts out the need to find a donor, and means we can produce more enzyme for the patient.
“The principles of using gene therapy of blood cells to treat patients with this disease can be applied to many other conditions which offers exciting prospects for patients and healthcare professionals. Our medicine is becoming safer, and better, and that can only be a good thing!”
Professor Simon Jones Consultant in Paediatric Inherited Metabolic Disease at the Manchester Centre for Genomic Medicine at Saint Mary’s Hospital, joint study lead, said: “Since having the gene therapy Ollie is no longer having weekly Elaprase infusions, but instead of seeing levels of the previously missing enzyme dropping we are seeing very high levels in his blood, and this is an extremely encouraging sign that the treatment is working.
Professor Jones, who is also a Medical Director of the National Institute for Health and Care Research (NIHR) Manchester Clinical Research Facility (CRF) at RMCH, added: “I have worked in researching treatments for children with rare genetic diseases for over twenty years and I have sadly seen many children lose their lives to these devastating conditions. This is a truly exciting development which could lead the way for treating similar genetic conditions and bring hope to other families.”
Ollie Chu is the first of five young children with Hunter syndrome to participate in this study. The research is jointly funded by the University of Manchester and by LifeArc, a self-funded, not-for-profit medical research organisation, and developed by researchers at MFT and The University of Manchester, working in partnership with the University of Edinburgh and Great Ormond Street Hospital (GOSH), where patients’ cells are taken to be modified with the missing gene in their specialist laboratories.
